1. Field of the Invention
This invention relates to bearing assemblies for rotating shafts and particularly to such assemblies incorporating fusible or frangible means for supporting shafts which may during operation become subjected to very high radial loads.
2. Description of the Prior Art
An example of such a bearing assembly is disclosed in U.S. Pat. No. 3,395,857 for supporting a compressor and turbine drive shaft in a gas turbine engine. The frangible means is designed to operate in the event of the loss for example of a turbine blade to permit radial movement of the drive shaft so as to prevent high radial loads being generated which could cause loss of engine attachment to the airframe. In this prior arrangement a plurality of frangible bolts serve to clamp a radial flange of an outer bearing housing to a support structure with mating surfaces in abutting relationship. The frangible bolts are designed to shear at a predetermined load and while this can be accurately predicted, the friction load between the mated surfaces is unknown which makes it extremely difficult to accurately predict the load at which shearing of the bolts will actually occur. Consequently, the prior arrangement may be unpredictable and unreliable in operation.
An objective of this invention therefore is to provide a bearing assembly which overcomes the aforementioned problems.